Antistatic compositions



2,723,246 Patented Nov. 8, 1955 United States Patent Ofiice ANTISTATIC COMPOSITIONS George H. Boyd, Bridgeton, N. J., and Mason Hayek, Wilmington, Del., assignors to E. I. du Pont de Nemonrs & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application February 27, 1953, Serial No. 339,452

8 Claims. (Cl. 26029.6)

This invention relates to anti-static compositions containing certain polymeric quaternary ammonium salts, and more particularly to dispersions of such polymers.

Onedisadvantage of textile fibers and particularly of fabrics prepared from synthetic hydrophobic materials, and of all textile fibers treated with conventional resin finishes, is that they tend to develop a static electrical charge. This charge is'objectionable, during the manufacture of the textile and in the finished garment. During manufacture the static charge on the fibers or fabrics interferes with their convenient handling during spinning, reeling, weaving and the like. Finished articles which are designed to drape like cotton or wool articles fail to do so properly due to their electrostatic charge and often cling uncomfortably to the wearer. Furthermore, such textiles tend to collect dust and lint, and the electric discharge itself is bothersome.

Many treating agents have been proposed to impart anti-static effects to textiles of this type. However, none of the proposed agentsis entirely satisfactory, either because of their effectiveness or their lack of resistance to washing and dry cleaning. Many of these anti-static agents are effectively transferred to the textile materials only with great difliculty. v

It is therefore an object of this invention to provide an effective anti-static composition which is highly resistant to washing and dry cleaning. Another object is the provision of an anti-static agent which imparts a durable anti-static effect to textile fibers and fabrics. Still another object is the provision of agents which may be applied by simplified treatments to the textiles rendering them substantially permanently anti-static. Other objects will appear as the description of the invention proceeds.

These and other objects are accomplished by a composition comprising one part of a water-soluble polymer or copolymer of a quaternary ammonium salt of a polymerizable nitrogen-containing vinyl compound as described more fully hereinafter; and from 0.2 to 0.8 molar equivalent of a dispersing agent of the class consisting of water-soluble salts of organic compounds of sulfuric, sulfonic, phosphoric acids and monocarboxylic acids, each acid having at least 12 carbon atoms in the molecule. The nitrogen-containing vinyl polymers are those of ethylenically unsaturated monomeric compounds which contain a vinylidene radical CH2=C in which is present their only non-aromatic carbon to carbon unsaturation, said vinylidene radical attached directly to a carbon atom having a double bond and being attached mediately to a nitrogen-containing group from the class consisting of tertiary amino and quaternary ammonium groups, said nitrogen-containing groups existing in the polymer in the form of their quaternary ammonium groups.

The quaternary salts used in preparing the compositions of the present invention may be made by any known method. One such method consists essentially of quaternizing an appropriate tertiary amine in water with the dimethyl sulfate, p-toluene sodium sulfonate or thelike, followed by polymerization as described in Example II 2 of copending application Serial No. 260,119, filed December 5, 1951.

Exemplary tertiary amine monomers which are usable in the preparation of the products of this invention include the dialkylaminoalkyl acrylates and methacrylates such as beta-diethylaminoethyl acrylate, beta-diethylaminoethyl methacrylate, and beta-dimethylaminoethyl methacrylate, and the vinylpyridines such as 4-vinylpyridine, Z-methyI-S-Vinylpyridine and 2,4-diethyl-5-vinylpyridine. Exemplary quaternary ammonium monomers which are usable include the beta-acrylyloxyalkyltrialkyl ammonium salts such as beta-acrylyloxyethyldiethylmethyl ammonium methylsulfate, the beta-alkacrylyloxyalkyltrialkyl ammonium salts such as beta-methacrylyloxyethyldiethylmethyl ammonium methylsulfate and beta-methacrylyloxyethyltrimethyl ammonium chloride, and the N-alkylvinylpyridinium salts such as l-ethyl-2-vinyl-pyridinium bromide, 1-butyl-2-vinyl-S-ethylpyridinium iodide and 1- methyl-4-vinylpyridinium-p-toluene sulfonate.

As noted above the quaternary ammonium salt may be a polymer or copolymer. The amount of comonomer may vary from 0% to by weight and, in some cases, as high as 95% of the material to be polymerized. The choice depends on one or more factors, such as the economics and the desired physical properties of the polymer. If a comonomer is used its amount generally is in the range of 5% to 75 by weight.

The term water-soluble is intended to mean that the compounds give homogeneous aqueous solutions which may be true solutionsor colloidal solutionss Those described herein are water-soluble when mixed at concentrations of at least 5% by weight in water at 70 to C.

The water-soluble salts of the organic sulfates mentioned above may be alkali metal, ammonium, or amine salts of alkyl sulfates or ether alcohol sulfates, examples of which may be mentioned:

Sodium dodecyl sulfate Potassium or ammonium dodecyl sulfate N-diethylcyclohexyl ammonium dodecyl sulfate Sodium salt of mixed dodecyl-tetradecyl sulfate Sodium salt of mixed dodecyl-tetradecyl alcohols condensed with about one mol of ethylene oxide Sodium octadecenyl (oleyl) sulfate Sodium salt of the sulfates of octadecenyl alcohol condensed with about one mol of ethylene oxide Sodium salt of mixed C10-C20 alkenyl sulfates (alcohols derived from the sodium reduction of sperm oil) The ether alcohols may be prepared by the conventional alkalicatalyzed condensation of the appropriate alcohol, which may be either saturated or unsaturated, with the desired number of mols of ethylene oxide. This may be from equal mols to as many as 10 or 12 mols of ethylene oxide for each mol of alcohol.

In the preparation of sulfonic acids, aliphatic and alkyl-substituted aryl sulfonic acids may be used. The former are commonly made by reaction of S02 and chlorine on the appropriate aliphatic hydrocarbon. Simple reaction of an alkylaryl hydrocarbon with sulfuric or chlorosulfonic acid produces sulfonation in the aromatic ring.

The alkyl phosphoric acid salts may be prepared by heating 2 to 3 mols of the appropriate alcohol or mixture of alcohols with one mol of P205, followed by neutralization with the desired base. This may be any alkali metal hydroxide, ammonium hydroxide or an amine. The preferred member is the diethanolamine salt of mixed monoand dialkyl phosphoric acids made from one mol of P20 and 3 mols of mixed primary straight-chain aliphatic alcohols of 8 to 14 carbon atoms.

The aliphatic monocarboxylic acids are the ordinary saturated or unsaturated fatty acids readily available on the market. Aromatic carboxylic acids are less common as dispersing agents. Although most of these are not of particular commercial importance, isopropyl naphthoic acid is quite useful.

The anti-static compositions may be prepared conveniently by adding an aqueous solution of the longchain alkyl sulfate, sulfonate, phosphate or carboxylate to an aqueous solution of the quaternary ammonium salt at room temperature. A reaction takes place between the polymeric quaternary ammonium salt and the long-chain anion. Usually enough short-chain alkyl sulfate anions are replaced by long-chain anions to throw out some of the quaternary compound from solution. The resulting product in some cases can be made into a homogeneous dispersion with a fine particle size by stirring vigorously at about room temperature during the reaction. Often it is necessary to use dispersing aids such as alcohols and hydrocarbon solvents, particularly in order to produce uniform, stable dispersions which can be readily extended with water. In other cases it is easier to dissolve the solid in an organic liquid such as ethanol or acetone, from which it can be readily applied to textiles by padding, followed by evaporation of the solvent.

The above dispersions may be applied to the textile or other material by padding, exhausting or other procedure, and if desired, may be applied in conjunction with any of the ordinary crease-resistant resin finishes for textiles as will be apparent from certain of the following examples. Among the resins used for this purpose are the methylol ureas, methylol melamines, their ethers and 1,3-bis(hydroxymethyl)-imidazolidone. These agents impart stiffness, crease-resistance, dimensional stability and other properties to textiles.

It has been found that ordinary loadings of these resins and finishes usually increase the static properties of textiles, and that the compositions of the present invention solve this particular problem Very effectively.

The agents are applied in amount to leave about 0.05% to about 2%, or even higher under extreme conditions, of active agent. The preferred range is usually from 0.25% to 0.9% of the methylsulfate salt or its equivalent of this salt after it has been reacted with the long-chain anion, based on the dry weight of the textile or other material treated. Usually these figures are about double for the long-chain alkyl quaternary salt.

The following examples are given by way of illustration and not by way of limitation, since any of the compounds given in the examples may be substituted by a stoichiometric amount of one of the equivalent salts or quaternary compounds mentioned above.

Example I 50 parts of a 30% aqueous solution of poly-beta methacrylyloxyethyldiethylmethyl ammonium methyl- Example I I Example I is repeated with the exception that 5 parts of sodium chloride is added to both the 30% aqueous solution of poly-beta-methacrylyloxyethyldiethylmethyl ammonium methylsulfate and the sodium hexadecenyl sulfate (25% to 30% aqueous paste). A trace of commercial silicone for preventing foam in aqueous systems is added to eliminate the foam. This product when diluted gives a better dispersion than in Example I.

Example 111 50 parts of a 30% aqueous solution of poly-betamethacrylyloxyethyldiethylmethyl ammonium methylsulfate is mixed with 2 parts of polyvinyl alcohol and 14 parts of water. A mixture of 33 parts of sodium hexadecenyl sulfate (25% to 30% aqueous paste) and 1 part of sodium chloride is added slowly with agitation. The resultant dispersion is stable and dilutions of it with water are stable.

Example IV Viscose rayon fabric is padded at 100% wet pick-up with an aqueous pad bath containing 15% by weight (based on the bath) of a commercial dimethylolurea (an aqueous solution containing about 20% monomeric and 4% partially condensed dimethylolurea); and 0.5% by weight of a commercial ammonium phosphate catalylst. The fabric is air-dried, baked 3 minutes at 350 F, padded with the product of Example V, rinsed and dried.

When measured as described above, the anti-static ratings at and 25% relative humidities are excellent and good, respectively. In contrast, a piece of the same fabric treated with the catalyst and resin without the quaternary ammonium compound has corresponding antistatic ratings of fair and poor.

The above padding operation is repeated with a methylated methylol melamine and a commercial (NH4)2HPO4 catalyst. In this case, anti-static ratings are very good and fair at 45 and 25% of relative humidities for the one bearing the anti-static agent, and poor for the piece of fabric bearing only the resin.

This padding operation is repeated again with 15% by weight of l,3-bis(hydroxymethyl)-imidazolidone; 0.5 by Weight of tartaric acid; and 1.5% by weight of the same polymeric quaternary ammonium anti-static agent. This treated textile has anti-static ratings of very good and good at 45 and 25 relative humidities. Without the anti-static agent the corresponding values are fair.

in every case, both with and without the anti-static agent, the pieces of textile have a pleasing hand and satisfactory degrees of crease-resistance and dimensional stability.

Example V When 18.4 parts by Weight of sodium hexadecenyl sulfate (25 to 30% aqueous paste) is mixed with a solution of 15 parts of poly-beta-methacrylyloxyethyldiethylmethyl ammonium methylsulfate in parts of water, the product is a white, viscous solid having a portion of the methylsulfate anions replaced by hexadecenyl sulfate anions. This solid is dissolved in ethanol and applied to fabrics made of nylon, polyacrylonitrile and polyethylene terephthalate at a loading of 0.5% by weight. The antistatic properties of the fabrics are greatly improved.

Example VI Similar results are obtained when Example V is repeated, using each of the following saltsinstead of sodiumhexadecenyl sulfate:

Sodium dodecyl sulfate Potassium dodecyl sulfate N-diethylcyclohexyl ammonium dodecyl sulfate Sodium salt of mixed dodecyl-tetradecyl sulfate (from technical dodecyl alcohol) Ammonium dodecyl sulfate Sodium octadecenyl (oleyl) sulfate Sodium salt of mixed Cur-C20 alkenyl sulfates (alcohols derived from sodium reduction of sperm oil) Sodium salt of sulfate of mixed dodecyl-tetradecyl alcohols, condensed (before sulfation) with one mol of ethylene oxide Sodium salt of sulfate of actadecenyl (oleyl) alcohol, condensed (before sulfation) with one mol of ethylene oxide Sodium salt of isopropylnaphthoic acid Sodium salt of C12-14 petroleum hydrocarbon sulfonate Sodium salt of C16-1s petroleum hydrocarbon sulfonate Sodium salt of dodecylbenzene sulfonic acid Sodium salt of dodecyltoluene sulfonic acid Diethanolamine salt of mixed monoand dilauryl phosphoric acids Sodium laurate Ammonium myristate Ammonium stearate Likewise, white to yellow viscous solids which impart anti-static properties to textiles are produced by repeating Example V, substituting for the polymer used there one of the following:

(1) The iodide of the same quaternary ammonium compound.

(2) The copolymer of equal parts of beta-methacrylyloxyethyldiethylamine and beta-vinyloxydimethylamine, quaternized with dimethyl sulfate (prepared as in Example IV of Hayek, Serial No. 339,453, filed February 27, 1953.

(3) The 75:25 copolymer of beta-methacrylyloxyethyltrimethyl ammonium methylsulfate and vinyl acetate (prepared as in Example VII of Hayek, Serial No. 339,453).

(4) The quaternized copolymer of Example VIII of Hayek, Serial No. 339,453, i. e., 50:50 copolymer of the methiodide of beta-methacrylyloxyethyldiethylamine with 4-vinyl-pyridine, reacted with dimethyl sulfate to quaternize the latter component.

Example VII When Example V is repeated using 51.8 parts by weight of sodium hexadecenyl sulfate (30% aqueous paste), a solid product of similar properties is obtained.

The present invention is particularly useful in reducing the anti-static properties of textile materials including fibers, yarns, threads and fabrics prepared from synthetic materials having high electrical resistance, such as those prepared from cellulose actate, nylon, polyacrylonitrile, and polyethylene terephthalate. Another advantage of the present invention is that the anti-static agents may be applied simultaneously with resinous, crease-resistant materials which normally increase the static efiectsof the textiles so treated, but when these resins are applied with the compositions of the present invention the static effects of the resin are obviated. This invention also provides a direct route to an anti-static finish which is not slimy in the presence of water.

It will be apparent that many widely diiferent embodiments of this invention may be made without departing from the spirit and scope thereof, and therefore it is not intended to be limited except as indicated in the appended claims.

We claim:

1. A composition suitable for imparting anti-static properties to materials which tend to accumulate a static charge which comprises, in proportion, one part of a polymer of an ethylenically unsaturated monomeric compound of which at least 5% contains a vinylidene radical in which is present the only non-aromatic carbon to carbon unsaturation, said vinylidene radical being attached directly to a carbon atom having a double bond and being attached mediately to a nitrogen-containing group from the class consisting of tertiary amino and quaternary ammonium groups, said nitrogen-containing groups existing in the polymer in the form of quaternary ammonium groups; and from 0.2 to 0.8 molar equivalent of a dispersing agent selected from the class consisting of monocarboxylic acids and organic compounds of sulfuric acid, sulfonic acid, and phosphoric acid, each acid having at least 12 carbon atoms in the molecule.

2. An aqueous anti-static dispersion which comprises, in proportion, 1 part by weight of a polymer of the dimethyl sulfate quaternary salt of an acrylyloxyalkyltrialkylamine in which each alkyl group has from 1 to 4 carbon atoms; and from 0.2 to 0.8 molar equivalent of a water-soluble'salt of an alkyl sulfate, the alkyl radical of which has from 12 to 20 carbon atoms.

3. A textile material bearing a dried film of the product of claim 2.

4. The composition of claim 2 in which the quaternary salt is the polymer of beta-methacrylyloxyethylmethyldiethyl ammonium methylsulfate together with sodium hexadecenyl sulfate.

5. The composition of claim 2 in which the quaternary salt is the polymer of beta-methacrylyloxyethylmethyldiethyl ammonium methylsulfate together with sodium stearate.

6. The composition of claim 2 in which the quaternary salt is the polymer of beta-methacrylyloxyethylmethyldiethyl ammonium methylsulfate together with sodium sulfonate of aliphatic hydrocarbons averaging about 15 carbon atoms.

7. The composition of claim 2 in which the quaternary salt is the polymer of beta-methacrylyloxyethylmethyldiethyl ammonium methylsulfate together with dodecyl benzene sodium sulfonate.

8. The composition of claim 2 in which the quaternary salt is the polymer of beta-methacrylyloxyethylmethyldiethyl ammonium methylsulfate together with sodium isopropyl naphthoate.

References Cited in the file of this patent UNITED STATES PATENTS 2,138,763 Graves Nov. 29, 1938 

1. A COMPOSITION SUITABLE FOR IMPARTING ANTI-STATIC PROPERTIES TO MATERIALS WHICH TEND TO ACCUMULATE A STATIC CHARGE WHICH COMPRISES, IN PROPORTION, ONE PART OF A POLYMER OF AN ETHYLENICALLY UNSATURATED MONOMERIC COMPOUND OF WHICH AT LEAST 5% CONTAINS A VINYLIDENE RADICAL IN WHICH IS PRESENT THE ONLY NON-AROMATIC CARBON TO CARBON UNSATURATION, SAID VINYLIDENE RADICAL BEING ATTACHED DIRECTLY TO A CARBON ATOM HAVING A DOUBLE BOND AND BEING ATTACHED MEDIATELY TO A NITROGEN-CONTAINING GROUP FROM THE CLASS CONSISTING OF TERTIARY AMINO AND QUATERNARY AMMONIUM GROUPS, SAID NITROGEN-CONTAINING GROUPS EXISTING IN THE POLYMER IN THE FORM OF QUATERNARY AMMONIUM GROUPS; AND FROM 0.2 TO 0.8 MOLAR EQUIVALENT OF A DISPERSING AGENT SELECTED FROM THE CLASS CONSISTING OF MONOCARBOXYLIC ACIDS AND ORGANIC COMPOUNDS OF SULFURIC ACID, SULFONIC ACID, AND PHOSPHORIC ACID, EACH ACID HAVING AT LEAST 12 CARBON ATOMS IN THE MOLECULE. 